The magnetization reversal of La0.7Sr0.3MnO3 (LSMO) epitaxial films deposited on 10 vicinal SrTiO3(001) substrates has been investigated at room temperature by using longitudinal magneto-optical Kerr microscopy. In the case when the magnetic field is applied parallel to the substrate steps, magnetization reversal proceeds first by the nucleation of magnetic domains with well-defined magnetic domain walls (DWs) oriented parallel to the step direction and then by DW propagation. No magnetic domains are found in the case when the magnetic field is applied perpendicular to the steps, in which case magnetization reversal proceeds by coherent rotation. Our results provide a direct visualization of the step-induced uniaxial magnetic anisotropy in half-metallic systems and for LSMO thickness up to 70 nm.